They found people in occupations requiring more movement had worse outcomes. But these people are probably also poorer, more stressed, drink more, smoke more. So it's hard to draw conclusions without controlling for this, to state the obvious.
I suspect the compulsory aspect of a job has something to do with it as well. When I injured my wrist, I simply stopped doing exercises that aggravated the pain. This is not really an option for someone whose livelihood depends on such physical activity.
Was going to say that. If it's done as a work, you _must_ do it every day, even when not feeling great, so you may lack adequate time to recover. I think adequate time to recover is the difference between exercise that strengthen us, and physical activity that just grinds us down.
Not to mention that those occupations are far more exposed to all manner of industrial chemicals and often have contempt for the precautions meant to keep them safe.
Just go to any construction site and observe how many are dealing with paints and solvents without any masks, let alone a properly fitted one.
You’ve been misinformed, as causality is not even within the purview of the experimental methodology of natural sciences.
In natural sciences, which include physics, you experimentally find that if you do X a few times, you get Z. That’s the extent of your hard claim. You can devise models that portray X as “causing” Z for simplicity, but the moment you start making claims about definite causal relationships you’d be making (implicitly or not) unfalsifiable claims about “underlying reality”, or in other words engaging in metaphysics. Maybe X causes Z, or maybe some unknown Y causes both you to do X and Z to occur—if you are evaluating a system of which you yourself are part, it is a fallacy to assume you possess complete knowledge about it.
That is simply not true except according to metaphysics. There are tests for causality in science which have no basis in metaphysics. This is why scientific conclusions about causality have thorough method sections and things like confidence intervals. A good paper is a discussion of eliminating alternative explanations. If new explanations emerge, you revise the paper.
Metaphysics exists (see what I did there?) because it says it does, not because science needs it somehow. We can’t take an existing paper and use metaphysics to add causality to it. We can only use metaphysics to weaken papers, and only metaphysically.
There are no tests that can prove causality due to reasons I outlined in my previous comment. Correlation can be reliable enough to be considered causation for practical purposes, but unless you possess some sort of transcendental sacred knowledge about the nature of the world you’re in, strictly speaking any “causation” is mostly correlation with a pinch of unfalsifiable pixie dust (or, more charitably, metaphysics).
A model, especially when described to a layperson, can offer various simplifications (such as electrons flying around their atoms like planets around a star, or X causing Z), but no one seriously considers a model as literally depicting reality.
An explanation with unfalsifiable claims is always slightly metaphysics.
Metaphysics, and philosophy in general, is how we have natural sciences, scientific method, reasoning, all those things. Dismissing it is not even wrong, it’s nonsensical because it’s not a sibling, it’s a parent.
If you read a scientific paper that talks about causation, you will see things like confidence intervals and assumptions. That’s what causality means, causal with some confidence under some set of circumstances and preconditions. That’s what science is.